GIMP 2.8 RC 1 includes OpenCL acceleration

The OpenCL hardware acceleration features in the Generic Graphics Library (GEGL) were originally developed as part of Google's Summer of Code in 2009 and 2011 and finished over the winter with sponsorship from AMD and help by MulticoreWare. On supported systems, this feature should greatly speed up processor intensive operations. Users have to start the application with the command line parameter GEGL_USE_OPENCL=yes to use OpenCL.